Btw - some say they find it easier with air compressor .. I've tried both and for me the grease gun works best

Got to agree partially on the grease gun approach but...............

Hydraulic fluid & G clamps (oooer missus etc) do it do me every time with loads of mess too.

Best way is to (try to) remove the brake system intact. If you can remove the (or have a spare) handlebar, then clamp the bar in a vice, reservoir upmost of course.

Then, if a single piston caliper, keep pumping (sorry the brake lever ) till the piston pushes out in a nice orderly British way.

However & this is where the G clamps come in, if you have dual pistons or more, then you need to stop the advance of the free ones in order to replace the stuck ones.

So, just pop the clamps on the ones that move freely, till the stuck ones move. You will need to adjust & mess about with clamps but its a lot cheaper than buying a set of brake piston removal tools which will only work on certain pistons.

What you are aiming for is for all the pistons to be at least 3/4's out. Then they can easily be removed with a set of plumbers pump pliers.

Its the way I get rusted and seized pistons out the callipers ..
Simply put... Put a surrogate bolt into the brake pipe hole to block it off, slacken the bleed nipple and put a grease gun onto the nipple... And pump.

Its amazing how easy it pushes out the piston so you can replace piston and seals etc

The only down side is having to clean out the grease in the calliper - but that's a very small price to pay and takes a couple of minutes

Btw - some say they find it easier with air compressor .. I've tried both and for me the grease gun works best

Hi Shaun,

nice one. I'll try that the next time I'm doing a calliper stripdown._________________Kindest regards

Btw - some say they find it easier with air compressor .. I've tried both and for me the grease gun works best

Got to agree partially on the grease gun approach but...............

Hydraulic fluid & G clamps (oooer missus etc) do it do me every time with loads of mess too.

Best way is to (try to) remove the brake system intact. If you can remove the (or have a spare) handlebar, then clamp the bar in a vice, reservoir upmost of course.

Then, if a single piston caliper, keep pumping (sorry the brake lever ) till the piston pushes out in a nice orderly British way.

However & this is where the G clamps come in, if you have dual pistons or more, then you need to stop the advance of the free ones in order to replace the stuck ones.

So, just pop the clamps on the ones that move freely, till the stuck ones move. You will need to adjust & mess about with clamps but its a lot cheaper than buying a set of brake piston removal tools which will only work on certain pistons.

What you are aiming for is for all the pistons to be at least 3/4's out. Then they can easily be removed with a set of plumbers pump pliers.

I hope that makes sense

Hi Howie,

yeah I've taken this route myself in the past on other machines and it wors fine.

Sometimes I've even swapped the dodgy calliper onto one of my other bikes, to pump it through. OK you have to re-bleed it but it's always good to have a bit of new brake fluid!_________________Kindest regards

The brake systems have been removed in tact so I can use the master cylinders to (try to) get the pistons out, then it looks like I've a few messy hours with a wire brush ahead of me.

The front brake was adequate for the performance of the bike, but obviously not what it should be. The brake pad retaining screw is seized in the calliper. It’s had a squirt of WD40, I’ll have to put the calliper back on the fork leg so I can get some leverage on it to release it. A new calliper is £116 on eBay so not bad for what it is. You don’t get many hours labour for that these days, but it’s not my way. If I find it needs pistons and seals then maybe a new one is the way to go, the new one comes with brake pads too. I’ll get a price for genuine parts as well, they’ve been surprisingly reasonable.

The rear brake hardly worked at all, and the rear disk is so worn the it has cracked. I think only one of the pistons has been moving so it’s been trying to bend the carrier to make the brake work. Same deal as the front really, with a new one costing £80 on eBay.

Surprised you’re using High Temperature paint on your callipers, surely they shouldn’t get that hot? I can see they’ll get radiated heat from the hot disk, but the calliper shouldn’t be in contact with anything really hot._________________Light is right.

No but hydraulic fluid does get hot. Not sure what temp it can get to in normal use?

But the main reason I use VHT or caliper specific paint is that it is more resilient to the effects of hydraulic fluid when bleeding the brakes & the spillage you can get. Unless you use DOT 5 (5.1) which doesn't have the same paint stripping qualities of DOT 4 but I have heard it's not as good as DOT 4???

First job is to get the callipers stripped and see if I need new pistons and seals. If I do, I'm be very tempted to just buy new callipers.

I hope new parts are not required, I do quite like dabbling and doing things my own way.

Pistons appear in good order, they look like stainless. Seals are OK but a bit of corrosion in the seal groove which made them tight on the pistons. The alloy body castings have suffered in the British weather but I think they're recoverable. Another plus is that I think I'm the first person to take them apart so no bodges._________________Light is right.

A genuine new front brake calliper is £116, and a new rear calliper is £82. Both come with new pads.

I've just dropped my front and rear callipers, foot rest hangers, foot rests and a bracket off to be vapour blasted at a cost of £70. The front pistons and seals are OK to re-use but the rear pistons and seals are shot, so there's another £25. I'll have to repaint the blasted callipers, and probably swap the corroded zinc calliper bolts for stainless.

I'm hoping that my rebuilt brakes will be as good as new, and that my painted finish might weather better than the anodised standard finish which has suffered so badly in the hands of the last seven 16 year old owners in just 17,000 miles.

I get the blasted parts back tomorrow, hope I feel happier about it when I see them._________________Light is right.

I picked up stainless fasteners at the auto-jumble this morning, and a two nice alloy torque arms, one for the rear brake of the special and one for the KH250. New rear pistons and seals are on order, as are new stainless bleed nipples._________________Light is right.